1. Field of the Invention
The present invention relates to ski bindings for automatically releasing a retained ski boot from a ski in response to the application of forces to the ski boot which could cause injury to the skier were the skier to remain mounted on the ski.
2. Description of the Prior Art
A great variety of ski bindings have been developed for securing a skier's respective ski boots to a pair of skis. In its simpler form, a ski binding provides means for strapping the ski boot to a ski to retain the skier mounted on the ski during a ski run. Because of the substantial likelihood of injuries to skiers resulting from twists, turns and falls wherein the skier remained mounted on the ski, there have been developed over the years a great number of safety bindings for releasing a retained ski boot from a ski in the event that forces applied to the ski boot exceeded a level anticipated as causing injury to the skier unless the skier were released from the ski. Such safety bindings have become quite sophisticated in recent years in light of the great popularity of skiing, and careful studies made of the operation of ski bindings and the causes of ski-related injuries to skiers.
One type of known safety binding is referred to as a cable binding. Cable bindings include cables connected at the forward end of a ski and forming a free loop extending rearwardly of a retained ski boot. The cable is drawn tightly against the heel portion of a ski boot in the binding, and a latch to which the cable is attached retains the cable against the boot. In the event that high forces are applied to the ski boot, means are provided for releasing the tension of the cable against the ski boot, whereby the boot can slip out of the binding and release the skier from the ski. Another type of safety binding includes heel and toe members mounted on a ski for engaging heel and toe portions of the ski boot to retain the boot on the ski. In general, the latter type of bindings includes means for latching either the toe or heel members in place in firm engagement with a ski boot disposed in the ski binding. When forces anticipated as being sufficient to cause injury to the skier occur, means are provided for unlatching the latched toe or heel member, whereby that member releases its engagement with the ski boot and the boot can slip out of the binding. Some popular bindings incorporating the toe and heel structure are popularly known under the names Cubco, Tyrolia, Marker, Americana, Gertsch, Look Nevada and Salomon.
Another type of binding which has become popular in recent years is a binding which has latching members for engaging structure associated with the sides of a ski boot rather than the toe or heel portion of the boot. This type of binding is described in U.S. Pat. No. Re. 26,972.
Despite the great advances which have been made in the development of ski bindings designed and constructed to protect skiers from injury, they have not proven entirely satisfactory as evidenced by the tremendous number of ski injuries which occur annually. This is largely due to the fact that existing ski bindings cannot be accurately set to effect the release of a retained ski boot in response to the application of injury-causing forces to the boot. This inaccuracy is, at least in part, caused by the fact that prior ski bindings are not environmentally secure so that ice, moisture and foreign matter frequently become lodged within the operating components of these bindings, thus altering their frictional characteristics and changing their respective release thresholds.
Some forces which are known to cause injury to skiers are not of a type to which present ski bindings respond. For example, forces of small magnitude but relatively long duration are a frequent cause of injury, and occur in the event of slow, twisting falls by skiers. On the other hand, some very high forces which are of very brief duration are not injury-causing forces, these occurring, for example, when a particularly aggressive skier proceeds down a slope taking vigorous turns and jumps in the process. One type of system for effecting release which is fully responsive to the foregoing forces, and indeed to other injury-causing forces as well, would be one incorporating transducers for generating electrical signals responsive to such forces, an electrical circuit for responding to these forces by controlling the operation of a mechanical member such as an electrical solenoid, and a mechanical ski binding for releasing from a cocked condition by such controlling member. However, for the same reason that known ski bindings are often ineffective in use, i.e., their environmental insecurity, known mechanical bindings are not compatible with electrical systems.
Prior safety bindings, including cable bindings, toe-and-heel bindings, and side-latching bindings, involve the pivotal movement of latching members for effecting release. Thus, the latching member swings about a pivot member in opposition to spring forces in order to effect release. An exception to this general statement is the binding described in U.S. Pat. No. 3,061,325 which incorporates latching members movable in a linear path in a recess in the sole of a ski boot. Ski bindings have been suggested incorporating magnetic latching members as well. However, the latter types of bindings have not been accepted by skiers.